Vibrator generator having swing unit, frame and elastic member

ABSTRACT

A vibrator includes a frame, a swing unit, and an elastic member. The swing unit is disposed within the frame and holds a magnet. The elastic member connects the swing unit and the frame. The swing unit is movable with respect to the frame while deforming the elastic member. The frame, the swing unit, and the elastic member are integrally molded with each other.

This application is a continuation application of U.S. application Ser.No. 17/007,121, filed Aug. 31, 2020, which is a continuation applicationof U.S. patent application Ser. No. 16/418,054, filed May 21, 2019,which is a divisional application of U.S. application Ser. No.15/363,879, filed Nov. 29, 2016, which is a continuation application ofU.S. patent application Ser. No. 13/891,656, filed May 10, 2013, whichclaims priority to and is based on Japanese Patent Application No.2012-116576 filed with the Japan Patent Office on May 22, 2012, theentire content of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to vibrators and vibration generators, andin particular to a vibrator capable of performing reciprocatory movementto generate vibration as well as to a vibration generator.

Description of the Related Art

A vibration generator that generates vibration by moving a vibrator isused. For example, a vibration generator that causes a vibrator having amagnet to perform a reciprocatory motion using a magnetic force is used.

The Document 1 listed below discloses a linear motor of a structurehaving a magnet as a moving unit within a frame unit as a stationaryunit and a plate spring provided between the magnet and the frame unitto hold the magnet. In this linear motor, the magnet moves with respectto the frame unit by a coil unit disposed so as to sandwich the magnetfrom above and underneath being excited.

-   -   [Document 1] Japanese Patent Publication Laying-Open No.        2010-36131

In the meantime, the vibration generator as described in the Document 1moves the magnet by urging the magnet by the plate spring. Accordingly,it is necessary to secure a relatively large space for the plate springto deform. However, there is a limit to increase a size of the vibratorrelative to the vibration generator, and it is difficult to increase avibration amount. In other words, it is necessary to increase a size ofthe vibration generator itself in order to increase the vibrationamount.

Further, the vibration generator as described in the Document 1 isconfigured by assembling the magnet, the plate spring, and the frameunit that are separate members from each other. Accordingly, the numberof steps required in order to assemble the vibration generator is large,and a process for manufacturing the vibration generator becomesrelatively complicated. Further, it is relatively difficult to ensureassembly accuracy, and variation in performance of vibration generators(individual variability) increases.

The present invention is made in order to address the above problems,and an object of the present invention is to provide a vibrator that canbe easily and accurately assembled and provide a large vibration forcerelative to a size of the vibration generator, as well as a vibrationgenerator.

SUMMARY OF THE INVENTION

In order to achieve the above object, according to one aspect of thisinvention, a vibrator is provided with: a frame; a swing unit disposedwithin the frame and for holding a magnet; and an elastic memberconnecting the swing unit and the frame, wherein the swing unit ismovable with respect to the frame while deforming the elastic member,and the frame, the swing unit, and the elastic member are integrallymolded with each other.

According to another aspect of this invention, a vibration generator isprovided with: the vibrators described above; and a coil disposed so asto face toward the swing unit of the vibrator, wherein the swing unitmoves with respect to the frame according to excitation of the coil.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a vibration generator according toone embodiment of this invention.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 .

FIG. 3 is a perspective view illustrating a structure of the vibrationgenerator.

FIG. 4 is a perspective view illustrating a region of a weight where agroove is provided.

FIG. 5 is a perspective view illustrating an arm unit.

FIG. 6 is a plan view illustrating a vibration generator according toone modified example of this embodiment.

FIG. 7 is a perspective view illustrating an arm unit.

FIG. 8 is a perspective view illustrating a region of a weight, where agroove is provided, of a vibration generator according to anothermodified example of this embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a vibration generator according to one embodiment of thisinvention will be described.

The vibration generator has such a structure that a portion of avibrator for holding a magnet is supported movably with respect to adifferent portion of the vibration generator. A coil is disposed nearthe magnet with a space from the magnet. The coil generates a magneticfield for changing at least one of a position and a posture of themagnet. The vibration generator generates a vibration force by thevibrator deforming according to excitation of the coil to cause themagnet to perform a reciprocatory motion. Specifically, the vibrationgenerator is a so-called linear type.

First Embodiment

FIG. 1 is a plan view illustrating the vibration generator according tothe one embodiment of this invention. FIG. 2 is a cross-sectional viewtaken along line A-A in FIG. 1 . FIG. 3 is a perspective viewillustrating a structure of the vibration generator.

In order to facilitate understanding of a layout of components of avibration generator 1, FIG. 1 shows a vibrator 50 and the like that areactually hidden behind a top plate 20 partially in solid lines. In FIG.1 , illustration of a flexible printed circuit (FPC: hereinafter alsosimply referred to as a circuit board) 10 is omitted except a partthereof.

In the following description, for vibration generator 1, there is a casein which a direction along an X axis in a coordinate system shown inFIG. 1 is referred to as a right-left direction (a positive directionalong the X axis from the original point is the rightward direction).Further, there is a case in which a direction along a Y axis in thecoordinate system shown in FIG. 1 is referred to as a front-backdirection (a positive direction along the Y axis from the original pointis the backward direction). Further, there is a case in which adirection along a Z axis in FIG. 2 (a vertical direction with respect toan XY plane in FIG. 1 ) is referred to as an up-down direction (apositive direction along the Z axis from the original point is theupward direction).

[Overall Structure of Vibration Generator 1]

As illustrated in FIG. 3 , vibration generator 1 generally includescircuit board 10, top plate 20, a bottom plate 30, a coil 40, andvibrator 50. As illustrated in FIG. 1 , vibrator 50 in this embodimentincludes a frame 55, a swing unit 60, and four arm units (one example ofelastic members) 80 (80 a, 80 b, 80 c, and 80 d).

As will be described later, vibration generator 1 generates vibration byswing unit 60 swinging. Swing unit 60 swings in a manner moving mainlyin the right-left direction with respect to a different region ofvibration generator 1 including vibrator 50 such as frame 55.Specifically, in this embodiment, a swing direction of swing unit 60 isthe right-left direction.

Vibration generator 1 as a whole is formed in a thin, substantial cuboidwhose vertical dimension is relatively small. Vibration generator 1 issmall such that external dimensions in the right-left direction and inthe front-back direction are on the order of 10 millimeters to 20millimeters. Vibration generator 1 has a box-shaped outline such that anupper surface and a lower surface of vibrator 50 having frame 55enclosing a lateral circumference are covered by top plate 20 and bottomplate 30, respectively.

As illustrated in FIG. 3 , vibrator 50 has a structure having swing unit60 within frame 55. Frame 55 and swing unit 60 are connected via fourarm units 80.

In this embodiment, frame 55 is formed in a rectangular and annularshape, for example, by bending one or more strip-shaped metal plates andthe like. In other words, frame 55 has a quadrangular, hollow, andcylindrical shape, within which swing unit 60 is disposed. It should benoted that frame 55 may not be completely annular. For example, frame 55can be partially discontinuous, or end portions of the one or more metalplates being partially overlapped with each other, so as to be formedannularly as a whole.

Swing unit 60 is formed substantially in a rectangular shape in a planarview. Swing unit 60 has a plate shape parallel to a horizontal plane(the XY plane in FIG. 1 ). Swing unit 60 is formed substantially in arectangular shape whose sides are each parallel to the front-backdirection or the right-left direction in the planar view except at fourcorners.

Swing unit 60 is disposed at a center portion of vibrator 50, that is, acenter portion of vibration generator 1, in the planar view. Asillustrated in FIG. 2 , swing unit 60 is disposed substantially parallelto coil 40 and facing toward coil 40.

Top plate 20 is flat-plated, and in a rectangular shape that issubstantially the same as that of an upper end portion of frame 55. Topplate 20 is disposed so as to be fitted in the upper end portion offrame 55. Bottom plate 30 is flat-plated, and in a rectangular shapethat is substantially the same as that of a lower end portion of frame55. Bottom plate 30 is disposed so as to be fitted in the lower endportion of frame 55. Top plate 20 and bottom plate 30 can be adhered orwelded to frame 55.

In this embodiment, a cutout 35 is provided at a part of a short side ofbottom plate 30. By providing cutout 35, an interior and an exterior ofvibration generator 1 are communicated.

As illustrated in FIG. 2 , circuit board 10 is configured such that afirst portion 10 a and a second portion 10 b are connected to each othervia a bent portion 10 c. First portion 10 a is provided with anelectrode connected to coil 40. Second portion 10 b is provided with anelectrode connected to a line for driving vibration generator 1. Bentportion 10 c is configured to have a width that can pass through cutout35. Circuit board 10 is disposed such that bent portion 10 c ispositioned in cutout 35, and that first portion 10 a and second portion10 b sandwich bottom plate 30 from above and underneath. Using suchflexible printed circuit 10 allows reducing the dimension of vibrationgenerator 1 in the up-down direction as compared to a case in which adouble-sided board is used. Further, since bottom plate 30 having asimple shape can be used, it is possible to reduce manufacturing cost ofvibration generator 1. Since bottom plate 30 is provided with cutout 35,circuit board 10 may not stick out of a casing, and it is possible toensure protection of circuit board 10.

Coil 40 is an air core coil configured by winding a conductive wire, andhaving a generally oval and flat plated shape. Specifically, coil 40 isa thin coil whose dimension in a direction of a winding axis is smallerthan a dimension in a direction orthogonal to the direction of thewinding axis. It should be noted that coil 40 can be configured byslicing a wound metallic foil, or by stacking sheet coils. Further, coil40 can have a circular shape or a polygon shape such as a quadrangularshape in the planar view.

Coil 40 is disposed on first portion 10 a of circuit board 10 such thatthe direction of the winding axis corresponds to the up-down direction.As illustrated in FIG. 1 , coil 40 is disposed at the center portion ofvibration generator 1 in the planar view so as to face toward swing unit60 as will be described later. Coil 40 is connected to the electrode(not depicted) formed on first portion 10 a of circuit board 10. It ispossible to make coil 40 conductive by applying a current to theelectrode (not depicted) formed on second portion 10 b of circuit board10 and exposed on an external surface of vibration generator 1.

As described above, swing unit 60 and coil 40 are covered by top plate20, bottom plate 30, and frame 55. With this, it is possible to preventa foreign matter such as dust from coming into vibration generator 1,and to keep vibration generator 1 operational. Further, since vibrationgenerator 1 is surrounded by top plate 20, bottom plate 30, and frame 55in a box-shaped manner, rigidity of vibration generator 1 itselfincreases. Therefore, it is possible to ensure that vibration generator1 generates vibration. Further, vibration generator 1 becomes easy to behandled when installed to an external device and the like.

In this embodiment, frame 55 and top plate 20 are made of a softmagnetic body such as iron, for example. As having a structure of beingsurrounded by frame 55 and top plate 20, vibration generator 1 isinsusceptible to a surrounding magnetic field and the like. Further,since a magnetic flux within vibration generator 1 may not easily leakoutside, influences to external devices and circuits are prevented.

On the other hand, bottom plate 30 is made of a non-magnetic material.Bottom plate 30 is made of a non-magnetic metallic material such asnon-magnetic stainless steel, for example. It should be noted thatbottom plate 30 is not limited to that made of a metallic material, andcan be made of a resin, for example. Further, frame 55 and top plate 20are not limited to those made of a soft magnetic body, and can be madeof a resin or a non-magnetic metallic material, for example.

[Detailed Structure of Vibrator 50]

As illustrated in FIG. 2 , swing unit 60 includes a magnet 61, a backyoke 63, and a weight 65. Magnet 61 is a permanent magnet and disposedin substantial center of swing unit 60. Back yoke 63 is a soft magneticbody such as iron, for example, and disposed on a top of magnet 61.Weight 65 is disposed around magnet 61 and back yoke 63 so as to holdmagnet 61 and back yoke 63. Weight 65 is made of a metal having arelatively large specific gravity, for example.

In this embodiment, as magnet 61, two magnets (magnets 61 a, 61 b)disposed respectively on right and left are provided. Magnet 61 a andmagnet 61 b are configured to have polarities opposite from each other.Specifically, a direction of the magnetic pole of magnet 61 a withrespect to coil 40 is opposite from that of magnet 61 b. It should benoted that, as magnet 61, it is possible to provide a single magnetmagnetized such that the magnetic directions with respect to coil 40 aredifferent between the right side and the left side. For example, magnet61 can be magnetized and polarized at a bottom side portion facingtoward coil 40 such that the north pole and the south pole are oppositealong the right-left direction. Further, three or more magnets 61 can bedisposed.

As illustrated in FIG. 1 , each arm unit 80 includes a weight jointportion 81, a frame joint portion 83, a beam portion 85, and a gateportion 87. Weight joint portion 81 is jointed to an outercircumferential surface of weight 65 out of swing unit 60. Frame jointportion 83 is jointed to an inner side surface of frame 55. Beam portion85 connects between weight joint portion 81 and frame joint portion 83.Gate portion 87 is formed on a side of weight joint portion 81. Each armunit 80 is integrally molded by an elastic resin, for example.

Beam portion 85 is a region of each arm unit 80 that mainly deflectswhen swing unit 60 moves with respect to frame 55. Each arm unit 80 isdisposed such that a longitudinal direction of corresponding beamportion 85 is substantially parallel to the Y axis direction.Specifically, beam portion 85 is formed such that its longitudinaldirection corresponds to a direction vertical to the swing direction ofswing unit 60.

In this embodiment, a cross section perpendicular to the longitudinaldirection of beam portion 85 (specifically, a cross section parallel toa ZX plane, hereinafter also simply referred to as the cross section ofbeam portion 85) is rectangular. A short side of this cross section issubstantially parallel to the swing direction of swing unit 60.

Four arm units 80 are connected to four corners (right rear, rightfront, left front, and left rear) of swing unit 60, respectively, suchthat swing unit 60 is supported in a well-balanced manner with respectto frame 55. Arm unit 80 a is disposed at right rear of weight 65. Armunit 80 b is disposed at right front of weight 65. Arm unit 80 c isdisposed at left front of weight 65. Arm unit 80 d is disposed at leftrear of weight 65.

Swing unit 60 has a shape symmetrical with respect both to a first planeand to a second plane. The first plane is a plane passing the center ofswing unit 60 in the planar view and parallel to an YZ plane. The secondplane is a plane passing the center of swing unit 60 and parallel to theZX plane. Further, each of four arm units 80 is disposed at a positionand in a posture both symmetrical with respect both to the first planeand to the second plane. Specifically, vibrator 50 is configuredsymmetrically with respect both to the first plane and to the secondplane.

As illustrated in FIG. 1 , grooves 67 (67 a, 67 b, 67 c, and 67 d) areprovided respectively in cutout portion 90 regions of weight 65 in whicharm units 80 are disposed (joints connecting weight 65 to arm units 80).

FIG. 4 is a perspective view illustrating the regions of weight 65 inwhich grooves 67 are provided.

Referring to FIG. 4 , grooves 67 are provided such that theirlongitudinal directions correspond to a direction that is not parallelto the swing direction of swing unit 60 (here, mainly the X axisdirection). Specifically, grooves 67 are provided such that theirlongitudinal directions correspond to the Z axis direction that issubstantially perpendicular to the swing direction of swing unit 60.

While grooves 67 are provided in this manner, arm units 80 are eachprovided with gate portion 87 projecting from weight joint portion 81 soas to be cut into corresponding grooves 67. Specifically, a jointingsurface between arm unit 80 and weight 65 is uneven along the directionvertical to the swing direction of swing unit 60.

[Description of Manufacturing Method of Vibrator 50]

In this embodiment, vibrator 50 is configured by frame 55, swing unit 60(magnet 61, back yoke 63, and weight 65), and four arm units 80 that areintegrally molded by insert molding. Vibrator 50 is manufactured in thefollowing manner.

First, back yoke 63 and magnet 61 are applied to weight 65. With this,swing unit 60 is configured. Further, frame 55 bent into a rectangularshape is prepared. Back yoke 63 and magnet 61 may be applied to eachother by spot welding or adhesion, for example.

Next, frame 55 and swing unit 60 are set in a molding tool of vibrator50.

Then, a resin to form arm units 80 is injected into the molding tool. Byremoving the molding tool, vibrator 50 can be obtained.

It should be noted that back yoke 63 and magnet 61 can be applied to aportion of weight 65 after the integral molding.

As the resin used for arm units 80 and the like (the resin used in theintegral molding), a silicon resin is used, for example. Alternatively,heat-resistant fluorine-based gum and the like can be used. By formingvibrator 50 using such gum, it is possible to improve heat resistance ofvibration generator 1. The elastic body is not limited to the aboveexamples, and various types can be used.

As weight 65 is provided with grooves 67 as described above, the resinis injected using grooves 67 as gates when integrally molding vibrator50. Therefore, it is possible to further facilitate the molding.

[Description of Operation of Vibration Generator 1]

In vibration generator 1, swing unit 60 can be moved with respect toframe 55 while deforming beam portion 85 of arm unit 80. Coil 40generates a magnetic field for causing swing unit 60 to perform areciprocatory motion with respect to frame 55. Upon excitation of coil40, swing unit 60 moves with respect to frame 55 accordingly. Vibrationgenerator 1 generates vibration by repeating the reciprocatory motion ofswing unit 60.

More specifically, when a current flows through coil 40, coil 40 isexcited, and a magnetic field is produced in the up-down direction. Uponproduction of the magnetic field, magnet 61 is affected by the magneticfield and a repelling and attracting force is produced. A force ofdisplacing leftward or rightward acts on swing unit 60 depending on thedirection of the magnetic field and an arrangement of the magnetic polesof magnet 61. Accordingly, swing unit 60 is moved toward either sidealong the right-left direction while causing each beam portion 85 todeflect. By an alternate current flowing through coil 40, swing unit 60performs a reciprocatory linear motion with respect to frame 55 in theright-left direction in the planar view according to the alternatecurrent. With this, vibration generator 1 generates a vibration force.

If a current value of the alternate current decreases and the magneticfield becomes smaller or vanishes, swing unit 60 attempts to return tothe center portion of vibration generator 1 in the planar view by arestoring force of arm units 80. At this time, as arm units 80 areelastic bodies, energy consumed by arm units 80 is relatively large.Therefore, the vibration is quickly attenuated.

In this embodiment, bottom plate 30 is configured by a non-magneticmaterial. Accordingly, a magnetic attracting force by magnet 61 is notgenerated between swing unit 60 and bottom plate 30. Swing unit 60 ismoved smoothly and efficiently according to the magnetic field generatedby coil 40. Therefore, it is possible to make vibration generator 1 thineven further and to operate appropriately.

[Description of Shape of Beam Portion 85]

In this embodiment, the shape of beam portion 85 of each arm unit 80 isdetermined such that vibrator 50 efficiently operates as describedbelow.

FIG. 5 is a perspective view illustrating arm unit 80.

As illustrated in FIG. 5 , in this embodiment, a dimension h of beamportion 85 in a longitudinal direction (a dimension of a long side of across section of beam portion 85) is larger than a dimension t of beamportion 85 in a lateral direction (a dimension of a short side of thecross section of beam portion 85). For example, dimension h in thelongitudinal direction is on the order of twice as large as dimension tin the lateral direction.

By setting the shape of beam portion 85 in this manner, a behavior ofswing unit 60 in the Z axis direction is relatively suppressed, and alarge vibration amount is obtained. Therefore, a force generated byexcitation of coil 40 can be efficiently transmitted in a main swingdirection of swing unit 60. It should be noted that an optimaldimensional ratio between dimension h in the longitudinal direction anddimension t in the lateral direction of beam portion 85 is appropriatelyderived by such a way as a simulation while changing parameters of thesedimensions.

Effects of Embodiment

As described above, in this embodiment, vibrator 50 is configured byintegrally molding frame 55, swing unit 60, and arm unit 80. Therefore,it is possible to assemble vibrator 50 easily and at high assemblyaccuracy. Since there is no time and effort for attachment of swing unit60 to frame 55 and the number of components can be reduced, it ispossible to reduce manufacturing cost of vibration generator 1. Further,since swing unit 60 and frame 55 are integrally formed, an attachmentbetween swing unit 60 and frame 55 may not become weak. Therefore, it ispossible to improve reliability of vibration generator 1 against impact.As any separate member such as a screw is not necessary for attachmentof swing unit 60 to frame 55, it is possible to make vibration generator1 further smaller, thinner, and lighter.

In this embodiment, as swing unit 60 and frame 55 are configured byseparate members, the number of components is reduced. Further, it ispossible to select the material of frame 55 appropriately whileproviding a plain structure that is easily assembled. Therefore, it ispossible to provide a configuration in which frame 55 acts as a magneticshield without additionally providing a member functioning as a magneticshield, for example.

Vibrator 50 is integrally molded including frame 55. Therefore, it ispossible to achieve a sufficiently large vibration force while keepingthe size of arm units 80 relatively small. It is possible to make thesize of swing unit 60 relatively large in proportion to the size ofvibrator 50, that is, in proportion to the size of vibration generator 1as a whole. Accordingly, it is also possible to achieve a relativelylarge vibration amount with small-sized vibration generator 1. Inparticular, in each arm unit 80, the longitudinal direction of beamportion 85 is the direction orthogonal to the swing direction, and beamportion 85 deforms efficiently in the swing direction. Therefore, it ispossible to obtain the effect of this embodiment more effectively.

Arm units 80 are disposed symmetrically with respect both to the firstplane and the second plane. Therefore, swing unit 60 is supported in awell-balanced manner, and vibration generator 1 can generate vibrationmore effectively.

A joint connecting arm unit 80 and weight 65 is uneven since groove 67is provided. In particular, groove 67 is provided such that itslongitudinal direction is a direction different from the swing directionof swing unit 60. It is possible to achieve a joint strength between armunit 80 and swing unit 60 sufficiently even without groove 67. However,by providing groove 67 in this manner, it is possible to ensureprevention of such a trouble that swing unit 60 is misaligned withrespect to arm unit 80 in the swing direction. Accordingly, it ispossible to further improve durability of vibration generator 1.

DESCRIPTION OF MODIFIED EXAMPLES

The vibrator can include a slit in the beam portion of the arm unit.

FIG. 6 is a plan view illustrating a vibration generator according toone modified example of this embodiment.

In FIG. 6 , a vibration generator 101 is illustrated in the same manneras in FIG. 1 . Vibration generator 101 is different from vibrationgenerator 1 in that arm units 180 (180 a, 180 b, 180 c, and 180 d)having a shape slightly different from that of arm units 80 areprovided. It should be noted that illustration of groove 67 is omittedin FIG. 6 . Other than the difference between arm units 80 and arm units180, vibration generator 101 has substantially the same configuration asvibration generator 1.

FIG. 7 is a perspective view illustrating arm unit 180.

As illustrated in FIG. 7 , arm unit 180 has a beam portion 185 whosewidth in the X axis direction is wider than that of beam portion 85 ofarm unit 80. At a center portion in the X axis direction of beam portion185, a slit 186 is provided along a longitudinal direction of beamportion 185. Slit 186 is provided so as to penetrate from an uppersurface to a lower surface of beam portion 185. Slit 186 is providedthroughout an entire region between weight joint portion 81 and framejoint portion 83. Specifically, providing slit 186 divides beam portion185 into two beams whose width in the X axis direction is narrow. Adimension of the width of beam portion 185 in the X axis direction and adimension of the width of slit 186 can be appropriately set such that adesired characteristic such as amplitude of vibrator 50 in vibration canbe achieved.

By providing beam portion 185 with slit 186 in this manner, a stressproduced in beam portion 185 when swing unit 60 is moved is reduced ascompared to a case in which beam portion 85 without slit 186 is used.Therefore, it is possible to relatively increase the lifetime of beamportion 185, and to further improve the durability of vibrationgenerator 101.

The groove can be provided only partially in the joint connecting theweight to the arm unit.

FIG. 8 is a perspective view illustrating a region of the weight, wherethe groove is provided, of the vibration generator according to anothermodified example of this embodiment.

As illustrated in FIG. 8 , weight 65 can be provided with a groove 267of a shape different from that of groove 67 according to the aboveembodiment. In this case, arm unit 80 is provided with a projectingportion 287 having a shape corresponding to the shape of groove 267 byusing groove 267 as a gate in molding of arm unit 80.

Groove 267 has a shape engraved downward from the upper surface ofweight 65 by a predetermined distance, for example. A lower end portionof groove 267 does not reach a lower surface of weight 65. Specifically,groove 267 is provided only partially in the joint connecting weight 65to arm unit 80.

It is possible to provide the same effect as in the above embodiment byproviding groove 267 having such a shape. Specifically, the jointingsurface between weight 65 and arm unit 80 is uneven, and arm unit 80does not easily misaligned with respect to weight 65 when swing unit 60swings. Further, since groove 267 is used as the gate in molding of armunit 80, it is possible to easily mold arm unit 80.

[Others]

It is not necessary to provide the groove of the weight and theprojecting portion of the arm unit. It is possible to ensure asufficient joint strength even if the gate position is not provided on aside of the weight.

It is possible to provide more than one coil. For example, it ispossible to provide the coils aligned right and left along the swingdirection of the swing unit. In this case, it is possible to use amagnet that is magnetized such that a side facing toward the coils isunipolar.

The shape of the frame and the shape of the vibrator are not limited torectangular in the planar view. It is possible to provide the shape invarious shapes such as an oval or polygonal shape for example.

The coil can be attached to a main circuit board of a device or the likethat uses vibration, and the swing unit can be driven by attaching thevibrator to the main circuit board having the coil. In other words, thevibration generator can be configured by using a coil mounted on acircuit board of a different device.

It is not necessarily required to attach the top plate to the vibrationgenerator. The top plate is useful for preventing dusts from coming intothe vibrator. However, the top plate may not be used in a case in whichthe vibration generator is contained in a narrow space, for example.

It is possible to use a printed circuit board (such as a double-sidedboard) instead of the flexible printed circuit. In this case, a printedcircuit board can be used instead both of the bottom plate and theflexible printed circuit, and the bottom plate may not be used.

According to these embodiments, the frame, the swing unit, and theelastic member are integrally molded with each other. Therefore, it ispossible to assemble easily and accurately, and to provide a vibratorwith which a large vibration force in proportion to the size of thevibration generator can be obtained, as well as a vibration generator.

It should be understood that the embodiments described above areillustrative and non-restrictive in every respect. The scope of thepresent invention is defined by the terms of the claims, rather than thedescription above, and is intended to include any modifications withinthe scope and meaning equivalent to the terms of the claims.

What is claimed is:
 1. A vibrator generator comprising: a frameincluding an annular shape; a swing unit; and an elastic member, whereinthe frame and the swing unit are connected via the elastic member, theelastic member includes a first joint portion connecting to the swingunit, a second joint portion connecting to the frame, and a beam portionconnecting between the first joint portion and the second joint portion,the beam portion is entirely arranged between the frame and the swingunit in a direction perpendicular to a swing direction of the swingunit, the width of the first joint portion or the width of the secondjoint portion is larger than the width of the beam portion connectingbetween the first joint portion and the second joint portion in theswing direction of the swing unit.
 2. The vibrator generator accordingto claim 1 comprising elastic members, wherein the elastic membersincludes the elastic member, the swing unit includes a magnet, themagnet is arranged between the elastic members in the swing direction ofthe swing unit.
 3. The vibrator generator according to claim 2, whereinthe swing unit includes a weight, the weight is arranged between theelastic members in the swing direction of the swing unit.
 4. Thevibrator generator according to claim 1, wherein the elastic member isformed of a resin.
 5. The vibrator generator according to claim 1,wherein a longitudinal direction of the beam portion is the directioncrossing the swing direction of the swing unit.
 6. The vibratorgenerator according to claim 1, wherein the beam portion deflects whenthe swing unit moves with respect to the frame in the swing direction ofthe swing unit.
 7. The vibrator generator according to claim 1comprising elastic members, wherein the elastic members includes theelastic member, the beam portions of the elastic members are arrangedbetween the frame, and the swing unit in the direction crossing theswing direction of the swing unit.